map -package:containers -package:basement -package:conduit -is:exact -package:monoidal-containers -package:case-insensitive -is:exact -package:pipes -package:base-compat-batteries -package:psqueues -package:base-compat -is:exact -package:invertible -package:os-string -package:integration -package:bytestring -package:text -package:aeson -package:filepath -package:regex-tdfa -is:exact package:vector-stream

Map a function over a Stream
Map a monadic function over a Stream
Execute a monadic action for each element of the Stream
Apply monadic function to each element and drop all Nothings